Upscayl is a cross-platform desktop application for AI-powered image upscaling, built with Electron and Next.js. It uses Real-ESRGAN models via the ncnn inference engine (Vulkan backend) to upscale images by 2x-4x. The application provides a rich UI with model selection, batch processing, double upscaling, custom model support, and extensive settings (GPU selection, tile size, TTA mode, metadata preservation). It also includes a cloud API (Upscayl Cloud) for server-side upscaling, documented via OpenAPI. The codebase is well-structured with clear separation between Electron main process and Next.js renderer, using Jotai for state management, Radix UI primitives, and a comprehensive localization system supporting 17 languages. While primarily an application, it contains pre-trained neural network model files (.param, .bin) that are research artifacts, giving it a hybrid character.